From b2bb430b3989a172bd17dd402e0510a67708c73d Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Fri, 13 Oct 2023 13:09:34 +0545
Subject: [PATCH] ddnuke: make block size & count cli options

---
 ddnuke.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/ddnuke.c b/ddnuke.c
index 388a144..02c6c21 100644
--- a/ddnuke.c
+++ b/ddnuke.c
@@ -65,9 +65,9 @@ static off_t get_size(int fd)
 	err(EX_DATAERR, "unknown type of file");
 }
 
-static void nuke(int fd, off_t offset, off_t max_size, unsigned char pattern)
+static void nuke(int fd, off_t block_size, off_t offset, off_t max_size, off_t flush_count, unsigned char pattern)
 {
-	static char mem[1024 * 1024];
+	char mem[block_size];
 	memset(mem, pattern, sizeof(mem));
 	if (pattern)
 		printf("Writing 0x%X to the output\n", pattern);
@@ -87,7 +87,7 @@ static void nuke(int fd, off_t offset, off_t max_size, unsigned char pattern)
 		/* This will round up to sizeof(mem) ... */
 		ret = write(fd, mem, sizeof(mem));
 		pos += ret;
-		if (ret != sizeof(mem)) {
+		if (ret != block_size) {
 			if (pos != max_size)
 				printf("\nread() returned %zi (wanted %zu)\n%'llu MB/s over entire run\n",
 					ret, sizeof(mem), mbps(&itime, &etime, pos));
@@ -95,11 +95,11 @@ static void nuke(int fd, off_t offset, off_t max_size, unsigned char pattern)
 		}
 
 		unsigned long long eta = speed ? (max_size - pos) / (speed * 1000 * 1000) : 0;
-		printf("\r\e[2K%'llu bytes %u%% (%'llu MB/s) (ETA ~%llum%llus)",
+		printf("\r%'llu bytes %u%% (%'llu MB/s) (ETA ~%llum%llus)\e[K",
 			(unsigned long long)pos, (unsigned)((pos * 100) / max_size), speed,
 			eta / 60, eta % 60);
 
-		if ((++fsync_pos % 32) == 0) {
+		if ((++fsync_pos % flush_count) == 0) {
 			speed = mbps(&stime, &etime, pos - last_pos);
 			last_pos = pos;
 			fflush(stdout);
@@ -119,6 +119,8 @@ static void usage(int status)
 		"Options:\n"
 		" -q            Run quietly\n"
 		" -y            Assume yes to all prompts\n"
+		" -b <size>     How many bytes to write at once. (default: 1Mib)\n"
+		" -f <count>    How many blocks to write before flush (stdout & disk). (default: 32)\n"
 		" -o <offset>   Position to start writing\n"
 		" -r            Write three times: 0x00, then 0xaa, then 0x55\n"
 	);
@@ -127,6 +129,8 @@ static void usage(int status)
 
 int main(int argc, char *argv[])
 {
+	off_t block_size = 1024 * 1024;
+	off_t flush_count = 32;
 	off_t offset = 0;
 	const char *file;
 	bool quiet = false;
@@ -136,8 +140,14 @@ int main(int argc, char *argv[])
 
 	setlocale(LC_NUMERIC, "en_US");
 
-	while ((o = getopt(argc, argv, "ho:qry")) != -1) {
+	while ((o = getopt(argc, argv, "hb:f:o:qry")) != -1) {
 		switch (o) {
+		case 'b':
+			block_size = atoll(optarg);
+			break;
+		case 'f':
+			flush_count = atoll(optarg);
+			break;
 		case 'o':
 			offset = atoll(optarg);
 			break;
@@ -186,10 +196,10 @@ int main(int argc, char *argv[])
 
 	off_t max_size = get_size(fd);
 
-	nuke(fd, offset, max_size, 0x00);
+	nuke(fd, block_size, offset, max_size, flush_count, 0x00);
 	if (random) {
-		nuke(fd, offset, max_size, 0xaa);
-		nuke(fd, offset, max_size, 0x55);
+		nuke(fd, block_size, offset, max_size, flush_count, 0xaa);
+		nuke(fd, block_size, offset, max_size, flush_count, 0x55);
 	}
 
 	return EX_OK;
-- 
2.39.2